MOTOR WINDING CONTAMINATION DETECTOR AND DETECTION

摘要

A method and apparatus for detecting motor contamination utilizes zero-sequence currents in a sensing coil to detect contamination. The detector includes a current transformer comprised of a magnetic core and a sensing coil wound about the core. A processor processes a sub-trip level current from the sensing coil to detect contamination. Three contamination detection methods, which may be used separately or in desired combination, are based on current trends, current leakage, and current clustering. An alarm is triggered when predetermined alarm criteria have been met.